Recent drive assistance systems using a car navigation system and the like, in many cases, present recommended routes from a current location to a destination point, and provide information related to a predicted fuel consumption for each case of taking the respective routes, that is, fuel-efficiency information. Hereinbelow, “fuel efficiency” means travelled distance of a vehicle per unit quantity of fuel. In such a case, a driver (person who drives the vehicle) refers to the recommended routes and the fuel-efficiency information for each of the recommended routes as provided, and selects a route. Conventionally, drive assistance systems as described for example in Patent Document 1 and Patent Document 2 are known as such drive assistance systems.
For example, in Patent Document 1, a server provided in a control center configures a fuel-efficiency information processing system. The server collects respective fuel-efficiency information of an unspecified large number of vehicles during driving along with moment-to-moment location information of those vehicles by radio communication. The server collects statistics of the fuel-efficiency information for each fuel-efficiency-influencing factor that influences the fuel efficiency such as upgrades and curves by referencing map information registered in a map database based on the collected location information.
Further, a fuel-efficiency information providing device for providing the fuel-efficiency information to the destination point is installed in each vehicle to configure the fuel-efficiency information processing system. The fuel-efficiency information providing device stores fuel-efficiency information based on a driving record of the device mounting vehicle for each fuel-efficiency-influencing factor. The fuel-efficiency information providing device handles averages and modes of the stored fuel-efficiency information as the fuel-efficiency information for each fuel-efficiency-influencing factor of the device mounting vehicle. The fuel-efficiency information providing device evaluates a degree of dispersion of the fuel-efficiency information of the device mounting vehicle relative to the fuel-efficiency statistics based on a comparison of the fuel-efficiency information for each fuel-efficiency-influencing factor based on the driving record of the device mounting vehicle with the fuel-efficiency information for each fuel-efficiency-influencing factor that has been statistically collected by the server. Accordingly, when the destination point is set by the driver in the car navigation installed in the vehicle, the fuel-efficiency information providing device acquires the fuel-efficiency statistics related to the fuel-efficiency-influencing factors existing in the route from the current location to the destination point from the server. At the same time, the fuel-efficiency information providing device searches the route to the destination point based on the acquired fuel-efficiency statistics and the evaluated degree of dispersion, and predicts the predicted fuel-efficiency consumption in the case of taking the route. The fuel-efficiency information providing device provides information including the predicted fuel-efficiency consumption, the fuel-efficiency-influencing factors existing in the searched route, and the influences of these fuel-efficiency-influencing factors on the fuel efficiency of the vehicle respectively to the driver.
Further, the drive assistance system of Patent Document 2 calculates a fuel efficiency from a starting point to a destination point and such a fuel efficiency for each of links, which are unit sections that are sectioned by a certain intersection to a subsequent intersection and the like, based on actual fuel-efficiency information of a plurality of vehicles that has been collected at a control center. The drive assistance system calculates predicted fuel-efficiency information from the current location to the destination point based on the calculated information related to the fuel efficiency, and fuel-efficiency-influencing factors such as time ranges when the information are acquired and road grades, and provides the predicted values to the driver for example via a display device.
As above, according to the drive assistance systems of Patent Document 1 and Patent Document 2, the driver is enabled to obtain the fuel-efficiency information required from the current location to the destination point and the presence of the fuel-efficiency-influencing factors. Accordingly, the driver can select routes and operate the vehicle with the information that is respectively provided as indexes.